Getting Wildlife (Safely) to the Other Side of the Road

More and more, mountain lions are tragically being injured or killed on the heavily-trafficked roads outside Los Angeles that cut through their mountain habitat. And as sprawling development consumes significant portions of the remaining green spaces in our country’s largest metropolitan areas, wildlife habitat is becoming increasingly fragmented by roads. But fortunately, there are ways to help animals safely avoid traffic through the creation of wildlife overpasses or tunnels. Here are a few of our favorites that are providing safe crossings for wildlife!

Mountain Lion Underpass

Banff National Park, which spans more than 2,000 square miles in Canada, has the most wildlife crossing structures located in any single place in the world – six overpasses and 38 underpasses help wildlife safely cross the four lane Trans-Canada Highway that runs through the park’s vast habitat areas. While wildlife use both the underpasses and overpasses, park experts have found that different species have definite preferences. Grizzly bears, wolves, elk, moose and deer prefer high, wide and short crossing structures, while black bears and cougars tend to choose underpasses that are long, low and narrow. Smaller animals such as snowshoe hare, porcupines and voles like to use the drainage culverts when there’s lots of traffic.

Desert Tortoise Passageway

A desert tortoise exits a culvert retrofitted for wildlife to safely cross beneath a highway in the Mohave Desert. Photo: William I. Boarman, U.S. Geological Survey.

Threatened desert tortoises were at risk of being run over by traffic as they tried to cross a highway that cuts through their habitat in the Mohave Desert. So wildlife experts and transportation officials teamed up to transform culverts running under the highway to serve as wildlife passageways. The culvert underpasses are now flush with the ground, and edged with small, soil-covered boulders to make it easy for the tortoises to enter and exit. The desert tortoise are using them, but at a leisurely pace – it took one tortoise seven hours of stopping and starting to get through one of the culvert underpasses!

Red Crab Crossings

Scientists estimate there are tens of millions of red crabs living on Australia’s Christmas Island. And every year as the crabs make their spectacular pilgrimage from the forest towards the ocean to breed, up to 500,000 die – many from being crushed by vehicles while crossing roads. To reduce the number of crabs killed by vehicles during the migration, ‘crab crossings’ are being created where roads cross main crab migration paths. Tunnels have been built under the road for the crabs and walls alongside the road help ‘funnel’ the migrating crabs through the underground crossings.

Safe Passage for Elephants

The elephant underpass in Africa is connecting families of elephants around Lewa with isolated herds living on Mount Kenya, which helps to increase the genetic diversity and overall health of the species. Photo: Lewa Wildlife Conservancy

Africa’s first dedicated elephant highway underpass in Kenya links wilderness areas on Mount Kenya’s highlands and the lower forests and plains. Many experts were skeptical at first – doubting that the elephants would be comfortable with passing beneath a freeway. However, the safe crossing for elephants is a tremendous success with hundreds of elephants travelling up and down every year. China and India have elephant underpasses too, and India even has elephant overpasses.

Salamander Tunnels

One night every spring, spotted salamanders leave their underground forest homes and migrate to wetland ponds to breed. Oftentimes they are killed crossing roads during migration. Photo: Mark Picard, FHWA

Wildlife enthusiasts in Amherst, Massachusetts volunteered for years to come out on a (usually) rainy evening, stop traffic and safely carry migrating salamanders across a busy road. They were trying to reduce the number of salamanders killed by traffic as they crossed the road on their migration from the forest to vernal pools for mating and to lay eggs. The local department of public works worked with conservation groups, the University of Massachusetts and others to create two underpasses for the salamanders to use during spring migration. The two tunnels were built at the salamanders crossing site, complete with fences to guide them into the tunnels and with openings at the top to provide the requisite dampness for the salamander’s travels.

Building a wildlife crossing is often an expensive, complex undertaking that requires expertise from wildlife biologists along with the coordination of a myriad of local, state and federal officials. Right now, in an initiative spearheaded by our California office and in partnership with wildlife experts and state transportation officials, we are working to create a wildlife overpass or tunnel across the 101 freeway in California that cuts through vital habitat for mountain lions and other wildlife. Please consider supporting our work to help create safe passages for wildlife and protect at-risk species.